Influence of strong local atmospheric disturbance on the near field strength of a low-frequency loop antenna located in the Earth's ionosphere

A low-frequency loop antenna located in the ionosphere can be an effective diagnostic tool for determining the parameters of strong local atmospheric disturbances. The source of such disturbances can be the intrusion of meteoroids into the atmosphere. The input impedance of the loop antenna in the ionosphere weakly depends on the parameters of the surrounding magnetoactive plasma, so even a relatively strong disturbance of the environment does not disrupt the matching of the loop with the transmitter. The article presents the results of numerical calculations of the time dependence of the near electric field strength of a loop antenna located in the ionosphere in the frequency range of 1...10 kHz. The parameters of the ionospheric plasma (ionization value, temperature, effective frequency of electron collisions) change in time under the influence of a strong local disturbance emerging in the atmosphere. It is shown that as the disturbance region approaches the antenna, the magnitude of the field strength deviates significantly from the background values, first in the direction of increase, and then in the direction of decrease, down to a value of the order of the field strength of such an antenna in free space. The duration of these disturbances of the field strength is in the range from 15 to 30 s with a change in the initial energy of the atmospheric disturbance from 1 to 10 PJ.